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Join our class as we explore the fascinating aspects of earthquakes and mountain building! Learn about P-waves, S-waves, faults, horsts, folds, and more! doesn't that sound cheesy?


the shaking of Earth's crust caused by a release of energy

Causes of earthquakes

eruption of a volcano, collapse of cavern, impact of meteor, for most it is the strain that builds up along faults


break in the lithosphere along which movement has occured

elastic-rebound theory

theory that describes when the plates deform through stress, and then move suddenly and snap back to original form, but moved relative to each other.


point at which first movement of an earthquake occurs


point on Earth's surface directly above the place where first movement occurs


type of boundary where earthquakes are shallow


type of boundary where earthquakes are also shallow


type of boundary where earthquakes are deep

body waves

waves that travel from the focus of an earthquake through Earth

P waves

waves that squeeze and stretch rock as they pass through Earth- can travel through any material

S waves

shear waves that cause material to move at right angles to the direction in which the waves are traveling, cannot travel through liquids or gases


the rate at which body waves move depends on the type and ____________ of the material through which they travel


the velocity of body waves is ________ when they are traveling through rigid and dense material

surface waves

earthquake waves that travel along Earth's surface

Love waves

cause particles to move from side to side, perpendicular to direction of wave movement

Rayleigh waves

travel more slowly than the other type of surface waves, cause particles of material to move in elliptical patterns, ripples


instrument that detects and records waves produced by earthquakes that may have originated hundreds of kilometers away


record sheet that is placed on a drum attached to the base

travel-time graph

shows the relationship between P-wave and S-wave arrival time and the distance from an earthquake's epicenter


number of seismographs needed to determine the location of an earthquake


measure of amount of energy released in an earthquake

Richter scale

measures intensity of ground movements, each whole number increase is a 31-fold increase in energy

moment magnitude

a measure that more accurately indicates the total energy involved in an earthquake, takes everything into consideration


occurs when loose soil temporarily takes on some of the properties of a liquid


a series of smaller earthquakes that occur after a major earthquake originating close to the focus of the larger one


underwater earthquakes and landslides cause huge ocean waves, a ____________.


The speed of a tsunami depends upon the ________ of the water

New Madrid

earthquake that occurred along the Mississippi River in Missouri, it was not along a fault, sediments in Mississippi, Ohio, and Missouri Rivers cause faults

seismic gaps

areas where a fault has not moved for a long period of time, places where stress is building up and an earthquake is expected to happen

shadow zone

area on Earth where seismographs do not detect P waves and S waves after an earthquake


area in Earth where the dense rock of the mantle meets the less dense rock of the crust

transition zone

separates the upper mantle from the denser lower mantle


large mass of rock that rises a great distance about its base

mountain belts

long belts that tend to follow convergent plate boundaries

continental margin

boundary between continental crust and oceanic crust


continental margin that occurs along a plate boundary


continental margin that does not occur along a plate boundary


accumulates along passive continental margins


measure of the amount of force applied over a given area


stress that involves squeezing


stress that involves pulling and stretching


stress that involves forces moving in opposite directions


happens when stress is applied to rocks at earth's surface


during plate collisions, stress can cause rock layers along continental margins to crumple into __________.


Folding occurs ________ Earth's surface


upfold in the rock layers


downfold in the rock layers


the two sides of a fold


steepness of limbs, reflects intensity of folding


compass direction of fold

hanging wall

part of fault above the fault plane


part of fault below the fault plane

normal fault

hanging wall moves down relative to the footwall, tension

reverse fault

hanging wall moves up relative to the footwall, compression

thrust fault

reverse faults where the fault plane dips 45 degrees or less from the horizontal, compressive stresses can move rock great distances

strike-slip fault

rocks on opposite sides of the fault plane move horizontally past each other; San Andreas fault


unlike a fault, a _____ is a break without movement

joint set

joints appear on the surface of a rock outcrop as a line, these lines can appear in parallel groups called ________ _____.

folded mountains

when two plates carrying continental crust collide, rocks can fold and crumple into ______ __________

dome mountain

nearly circular folded mountain, individual, isolated structures that tend to occur in areas of essentially flat-lying sedimentary rocks, bent upward in a dome shape as a result of uplifting forces


type of dome mountain, igneous intrusion, youngest rock at center


type of dome mountain, uplifting forces arch rock upward, youngest rocks on edge

fault-block mountains

formed by tension, uplift


a block of crust is thrown up between two normal faults


large blocks of crust have dropped between two normal faults

Marcoli scale

scale to measure earthquake based on people's observations

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